Experimental study of copper toxicity and some stress biomarkers in Macrobrachium scabriculum (Heller, 1862)

A laboratory experiment on copper toxicity in Macrobrachium scabriculum or Chameleon shrimp was performed to understand the adverse effect of copper sulfate, commonly used as antiparasitic medication against Ichthyophthirius multifilis or Ick. Mortality rate was observed to be over 80% at dosage of 5 µM and above, equivalent to about 0.32 mg.L−1 or higher of ionic copper. The species exhibited a greater resistance against copper toxicity than many other shrimp/prawn species as its survivability was quite high even under relatively higher copper concentrations. The LC50 value after 168 h of exposure was 3.12 ± 0.13 µM of copper sulfate or 0.78 ± 0.25 mg.L−1 in terms of Cu2+. Lipid peroxidation activity along with catalase and superoxide dismutase was selected as oxidative stress biomarkers. All the three biomarkers appeared to be more or less equally responsive to the stress level. One-way ANOVA performed on the data set ensured the statistical significance of the data with the rejection of null.